Earlier this year, I flew DFW-MAD on the 763 and returned via JFK on the 75L.
While I agree with other FTers about the D/G seats on the 763, I thought the seat was a wee bit wider and better on the 75L.

As for IFE, I usuallly use my 15" Macbook Pro. The IFE on the 75L is widescreen and fairly high quality. IMHO, while I like the 10" Galaxy Tablets, the display is a bit dim, even when I adjusted brightness to max.... so, with some movies, I found many scenes hard to see, even in a darkened cabin.



p.s. Frankly, however, since I am an upgrader working for a non-profit that can never pay F or J fares, I am so glad to be upfront that the minor differences between 75L and 763 seem of little importance!